Surveillance following orchiectomy alone has gained popularity in the management of clinical stage I non-seminomatous germ cell tumours (NSGCT) of the testis. However, long-term follow-up of the retroperitoneal nodes can be difficult. We analysed the results of 71 consecutive patients followed for more than 1 year. Fifty men (70.5%) remain disease-free and 21 (29.5%) have relapsed. Relapses occurred 2 to 36 months after orchiectomy (median 6 months). Retroperitoneal nodes were involved in 12 cases (17%). In only one patient were retroperitoneal metastases diagnosed when smaller than 2 cm and in four they were diagnosed when larger than 5 cm. Furthermore, the late relapses occurred in the retroperitoneal nodes. After treatment of metastases, 69 patients (97%) are alive, disease-free and off therapy. As retroperitoneal relapses do not occur after a properly executed retroperitoneal lymph node dissection (RPLND) and ejaculation problems can be avoided with unilateral RPLND, it is suggested that RPLND can be used for clinical stage I NSGCT of the testis in experienced surgical centres, with the advantage of an easier follow-up.